Quinine as chiral discriminator for determination of enantiomeric excess of diethyl 1,2-dihydroxyalkanephosphonates

Zwitterionic Phosphorylated Quinines as Chiral Solvating Agents for NMR Spectroscopy

“…Quinine has been extensively studied as a chiral solvating agent for 1 H, 19 F, 31 P, and 119 Sn nuclear magnetic resonance (NMR) spectroscopy, and it is able to induce anisochrony of the enantiotopic nuclei of various substrates. [8][9][10] The multifunctional nature of quinine enables modulation of its enantiodiscrimination potential by selective modifications. [8][9][10] The multifunctional nature of quinine enables modulation of its enantiodiscrimination potential by selective modifications.…”

Effective fungal catalyzed synthesis of P-chiral organophosphorus compounds

“…This allowed us to determine each stereoisomer of the examined compound. 16 As shown in 31 P NMR spectra in Figure 1, by means of the preincubation of biocatalyst's cells in the presence of methyl-isopropyl ketone, only one stereoisomer of the racemic mixture of the substrate was transformed (Fig. 1B).…”

“…After filtration, the organic phase was evaporated and the product analyzed by means of 31 P NMR spectroscopy using quinine as a chiral discriminator. 16 After the addition of methyl-iso-propyl ketone, the (S p S)-stereoisomer was obtained with a yield of up to 20%, while the application of oxalacetic acid allowed us to gain the pair of the (R p R) and (S p R) diastereoisomers with chemical yields of up to 48%. In every case, the enantiomeric excess was >99%.…”

Enantiodifferentiation of α‐hydroxyalkanephosphonic acids in 31P NMR with application of α‐cyclodextrin as chiral discriminating agent

“…The reports on direct determination of the enantiopurity of hydroxyphosphonates by simple addition of suitable chiral solvating agents (CSA) to the analyzed solution are rather scarce. Enantiomers of a series of diethyl hydroxyphosphonates were analyzed by 1 H or 31 P NMR in the presence of cinchona alkaloids [44][45][46][47] (quinine, cynchonine, and cynchonidine) or 1-(1-naphtyl)ethylamine 48 applied as CSA. For a particular case (diethyl hydroxyphenylmetanephosphonate) successful use of 1,1,2-triphenyl-1,2-ethanediol was also reported.…”